#ifndef TZFILE_H

#define TZFILE_H

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/

/*
** This header is for use ONLY with the time conversion code.
** There is no guarantee that it will remain unchanged,
** or that it will remain at all.
** Do NOT copy it to any system include directory.
** Thank you!
*/

/*
** Information about time zone files.
*/

#ifndef TZDIR
#define TZDIR    "/usr/local/etc/zoneinfo" /* Time zone object file directory */
#endif /* !defined TZDIR */

#ifndef TZDEFAULT
#define TZDEFAULT    "localtime"
#endif /* !defined TZDEFAULT */

#ifndef TZDEFRULES
#define TZDEFRULES    "posixrules"
#endif /* !defined TZDEFRULES */

/*
** Each file begins with. . .
*/

#define    TZ_MAGIC    "TZif"

struct tzhead {
    char    tzh_magic[4];        /* TZ_MAGIC */
    char    tzh_version[1];        /* '\0' or '2' or '3' as of 2013 */
    char    tzh_reserved[15];    /* reserved; must be zero */
    char    tzh_ttisgmtcnt[4];    /* coded number of trans. time flags */
    char    tzh_ttisstdcnt[4];    /* coded number of trans. time flags */
    char    tzh_leapcnt[4];        /* coded number of leap seconds */
    char    tzh_timecnt[4];        /* coded number of transition times */
    char    tzh_typecnt[4];        /* coded number of local time types */
    char    tzh_charcnt[4];        /* coded number of abbr. chars */
};

/*
** . . .followed by. . .
**
**    tzh_timecnt (char [4])s        coded transition times a la time(2)
**    tzh_timecnt (unsigned char)s    types of local time starting at above
**    tzh_typecnt repetitions of
**        one (char [4])        coded UT offset in seconds
**        one (unsigned char)    used to set tm_isdst
**        one (unsigned char)    that's an abbreviation list index
**    tzh_charcnt (char)s        '\0'-terminated zone abbreviations
**    tzh_leapcnt repetitions of
**        one (char [4])        coded leap second transition times
**        one (char [4])        total correction after above
**    tzh_ttisstdcnt (char)s        indexed by type; if 1, transition
**                    time is standard time, if 0,
**                    transition time is wall clock time
**                    if absent, transition times are
**                    assumed to be wall clock time
**    tzh_ttisgmtcnt (char)s        indexed by type; if 1, transition
**                    time is UT, if 0,
**                    transition time is local time
**                    if absent, transition times are
**                    assumed to be local time
*/

/*
** If tzh_version is '2' or greater, the above is followed by a second instance
** of tzhead and a second instance of the data in which each coded transition
** time uses 8 rather than 4 chars,
** then a POSIX-TZ-environment-variable-style string for use in handling
** instants after the last transition time stored in the file
** (with nothing between the newlines if there is no POSIX representation for
** such instants).
**
** If tz_version is '3' or greater, the above is extended as follows.
** First, the POSIX TZ string's hour offset may range from -167
** through 167 as compared to the POSIX-required 0 through 24.
** Second, its DST start time may be January 1 at 00:00 and its stop
** time December 31 at 24:00 plus the difference between DST and
** standard time, indicating DST all year.
*/

/*
** In the current implementation, "tzset()" refuses to deal with files that
** exceed any of the limits below.
*/

#ifndef TZ_MAX_TIMES
#define TZ_MAX_TIMES    2000
#endif /* !defined TZ_MAX_TIMES */

#ifndef TZ_MAX_TYPES
/* This must be at least 17 for Europe/Samara and Europe/Vilnius.  */
#define TZ_MAX_TYPES    256 /* Limited by what (unsigned char)'s can hold */
#endif /* !defined TZ_MAX_TYPES */

#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS    50    /* Maximum number of abbreviation characters */
                /* (limited by what unsigned chars can hold) */
#endif /* !defined TZ_MAX_CHARS */

#ifndef TZ_MAX_LEAPS
#define TZ_MAX_LEAPS    50    /* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */

#define SECSPERMIN    60
#define MINSPERHOUR    60
#define HOURSPERDAY    24
#define DAYSPERWEEK    7
#define DAYSPERNYEAR    365
#define DAYSPERLYEAR    366
#define SECSPERHOUR    (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY    ((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR    12

#define TM_SUNDAY    0
#define TM_MONDAY    1
#define TM_TUESDAY    2
#define TM_WEDNESDAY    3
#define TM_THURSDAY    4
#define TM_FRIDAY    5
#define TM_SATURDAY    6

#define TM_JANUARY    0
#define TM_FEBRUARY    1
#define TM_MARCH    2
#define TM_APRIL    3
#define TM_MAY        4
#define TM_JUNE        5
#define TM_JULY        6
#define TM_AUGUST    7
#define TM_SEPTEMBER    8
#define TM_OCTOBER    9
#define TM_NOVEMBER    10
#define TM_DECEMBER    11

#define TM_YEAR_BASE    1900

#define EPOCH_YEAR    1970
#define EPOCH_WDAY    TM_THURSDAY

#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))

/*
** Since everything in isleap is modulo 400 (or a factor of 400), we know that
**    isleap(y) == isleap(y % 400)
** and so
**    isleap(a + b) == isleap((a + b) % 400)
** or
**    isleap(a + b) == isleap(a % 400 + b % 400)
** This is true even if % means modulo rather than Fortran remainder
** (which is allowed by C89 but not C99).
** We use this to avoid addition overflow problems.
*/

#define isleap_sum(a, b)    isleap((a) % 400 + (b) % 400)

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* !defined TZFILE_H */
